This is a longitudinal study of children of affectively ill and well parents, from early childhood to adolescence. The research objectives are: (a) to follow the course of children's psychosocial development, and (b) to investigate the relation of parents' diagnoses, family history, and family functioning and family stress factors to children's functioning. Assessment of child functioning includes psychiatric interviews with the children and their parents, other parent and child interviews. Models for longitudinal assessments have been worked out. Analyses of the data are well underway.